In the related art, there is a known laser microscope with which light stimulation and fluorescence observation a specimen are performed (for example, see Patent Literature 1). A relatively high light intensity is required in order to obtain a response when performing light stimulation of a specimen, whereas a relatively low light intensity is often demanded for fluorescence observation in order to avoid color fading.
A laser microscope disclosed in Patent Literature 1 is provided with an acousto-optic device like an AOTF (Acoust-Optic Tunable Filter), and the intensity of laser light is modulated by using the acousto-optic device when performing light stimulation and fluorescence observation a specimen.